Multi-Position Valves for Fracturing and Sand Control and Associated Completion  Methods

ABSTRACT

A completion tubular is placed in position adjacent the zone or zones to be fractured and produced. It features preferably sliding sleeve valves one series of which can be put in the wide open position after run in for gravel packing and fracturing zones one at a time or in any desired order. These valves are then closed and another series of valves can be opened wide but with a screen material juxtaposed in the flow passage to selectively produce from one or more fractured zones. An annular path behind the gravel is provided by an offset screen to promote flow to the screened production port. The path can be a closed annulus that comes short of the production port or goes over it. For short runs an exterior screen or shroud is eliminated for a sliding sleeve with multiple screened ports that can be opened in tandem.

FIELD OF THE INVENTION

The field of the invention relates to completion techniques involvingfracturing and more particularly the ability to gravel pack and fracturediscrete segments of a formation in a desired order through dedicatedvalved ports followed by configuring another valve for screened sandcontrol duty to let production begin. A crossover tool and a separaterun for sand control screens after the fracturing operation is notrequired.

BACKGROUND OF THE INVENTION

Typical completion sequences in the past involve running in an assemblyof screens with a crossover tool and an isolation packer above thecrossover tool. The crossover tool has a squeeze position where iteliminates a return path to allow fluid pumped down a work string andthrough the packer to cross over to the annulus outside the screensections and into the formation through, for example, a cemented andperforated casing or in open hole. Alternatively, the casing could havetelescoping members that are extendable into the formation and thetubular from which they extend could be cemented or not cemented. Thefracture fluid, in any event, would go into the annular space outsidethe screens and get squeezed into the formation that is isolated by thepacker above the crossover tool and another downhole packer or thebottom of the hole. When a particular portion of a zone was fractured inthis manner the crossover tool would be repositioned to allow a returnpath, usually through the annular space above the isolation packer andoutside the work string so that a gravel packing operation could thenbegin. In the gravel packing operation, the gravel exits the crossovertool to the annular space outside the screens. Carrier fluid goesthrough the screens and back into the crossover tool to get through thepacker above and into the annular space outside the work string and backto the surface.

This entire procedure is repeated if another zone in the well needs tobe fractured and gravel packed before it can be produced. Once a givenzone was gravel packed, the production string is tagged into the packerand the zone is produced.

There are many issues with this technique and foremost among them is therig time for running in the hole and conducting the discrete operations.Other issues relate to the erosive qualities of the gravel slurry duringdeposition of gravel in the gravel packing procedure. Portions of thecrossover tool could wear away during the fracking operation or thesubsequent gravel packing operation, if the zone was particularly long.If more than a single zone needs to be fractured and gravel packed, itmeans additional trips in the hole with more screens coupled to acrossover tool and an isolation packer and a repeating of the process.The order of operations using this technique was generally limited toworking the hole from the bottom up. Alternatively, one trip multi-zonesystems have been developed that require a large volume of proppantslurry through the crossover tool and that increases the erosion risk.

What the present invention addresses are ways to optimize the operationto reduce rig time and enhance the choices available for the sequence oflocations where fracturing can occur. Furthermore, through a uniquevalve system, fracturing can occur in a plurality of zones in anydesired order followed by operating another valve to place filter mediain position of ports so that production could commence with a productionstring without having to run screens or a crossover tool into the well.These and other advantages of the present invention will be more readilyapparent to those skilled in the art from the description of the variousembodiments that are discussed below along with their associateddrawings, while recognizing that the claims define the full scope of theinvention.

SUMMARY OF THE INVENTION

A completion tubular is placed in position adjacent the zone or zones tobe fractured and produced. It features preferably sliding sleeve valvesone series of which can be put in the wide open position after run infor gravel packing and fracturing zones one at a time or in any desiredorder. These valves are then closed and another series of valves can beopened wide but with a screen material juxtaposed in the flow passage toselectively produce from one or more fractured zones. An annular pathbehind the gravel is provided by an offset screen to promote flow to thescreened production port. The path can be a closed annulus that comesshort of the production port or goes over it. For short runs an exteriorscreen or shroud is eliminated for a sliding sleeve with multiplescreened ports that can be opened in tandem.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of an embodiment with a proppant control shroudshown in the run in position;

FIG. 2 is the view of FIG. 1 with a valve open for proppant depositionand fracturing;

FIG. 3 is the view of FIG. 2 with the frac valve closed and theproduction valve open with a screen in the flow path of the productionvalve;

FIG. 4 is the view of FIG. 1 but with an alternative embodiment wherethe proppant shroud straddles the production valve;

FIG. 5 is the view of FIG. 4 with the fracture and proppant depositionvalve open;

FIG. 6 is the view of FIG. 5 with the fracture and proppant depositionvalve closed and the production valve open with a screen in the flowpath;

FIG. 7 is an alternative embodiment with no external proppant shroud andinstead having a sleeve to open multiple production ports with screenedopenings and a frac valve all shown in a closed position for run in;

FIG. 8 is the view of FIG. 7 with the frac valve in the wide openfracturing position;

FIG. 9 is the view of FIG. 8 with the frac valve closed and theproduction sliding sleeve in the open position;

FIG. 10 is a view of a frac valve in the closed position;

FIG. 11 is the view of FIG. 10 with the frac valve in the open position;

FIG. 12 is the view of FIG. 11 with the frac valve in the open positionand an insertable screen in position for production;

FIG. 13 is the view of the insertable screen shown in FIG. 12;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 is a schematic illustration of a wellbore 10 that can be cased orin open hole. There are perforations 12 into a formation 14. A string 16is shown in part if FIG. 1 to the extent it spans a production intervaldefined between seals or packers 18 and 20. These seal locations can bepolished bores in a cased hole or any type of packer. The two barriers18 and 20 define a production interval 22. While only one interval isshown the string 16 can pass through multiple intervals that preferablyhave similar equipment so that access to them can occur in any desiredorder and access can be to one interval at a time or multiple intervalstogether.

The string 16 for the interval 22 that is illustrated has a frac valve24 that is preferably a sliding sleeve shown in the closed position inFIG. 1 for run in. Valve 24 regulates opening or openings 25 and is usedin two positions. The closed position is shown in FIG. 1 and the wideopen position is shown in FIG. 2. In the FIG. 2 position, gravel slurrycan be squeezed into the formation 14 leaving the gravel 28 in theannular interval 22 just outside the proppant screen or shroud 29.Shroud 29 is sealed on opposite ends 30 and 32 and in between defines anannular flow area 34. While the shroud 29 is shown as one continuousunit, it can also be segmented with discrete or interconnected segments.The proppant 28 stays in the interval 22 and the carrier fluid is pumpedinto the formation 14 to complete the fracturing operation. At thatpoint the valve 24 is closed and excess proppant 28 that is still in thestring 16 can be circulated out to the surface using, for example,coiled tubing 36.

At this point the production valve 26 which is preferably a slidingsleeve with a screen material 38 in or over its ports is brought intoalignment with ports 40 and production from the formation 14 begins.Alternatively, the screen material 38 can be fixed to either side of thestring 16. In short, the open position of production valve 26 results inthe production flow being screened regardless of screen position andscreen type. Flow can take a path of less resistance through the flowarea 34 to reach the port 40. While such flow avoids most of the gravelpack 28 by design, the presence of passage 34 allows a greater flow toreach the ports 40 so as not to impede production. The presence of ascreen material 38 at ports 40 serves to exclude solids that may havegotten into passage 34 through the coarse openings in shroud 29. Thescreen material 38 can be of a variety of designs such as a weave,conjoined spheres, porous sintered metal or equivalent designs thatperform the function of a screen to keep gravel 28 out of the flowpassage through string 16.

It should be noted that while only a single port 25 and 40 are shownthat there can be multiple ports that are respectively exposed byoperation of valves 24 and 26. While valves 24 and 26 are preferablylongitudinally shiftable sliding sleeves that can be operated with ashifting tool, hydraulic or pneumatic pressure or a variety of motordrivers, other styles of valves can be used. For example, the valves canbe a sleeve that rotates rather than shifts axially. While a singlevalve assembly in an interval between barriers 18 and 20 is illustratedfor valves 24 and 26 and their associated ports, multiple assemblies canbe used with either discrete sleeves for a given row of associatedopenings or longer sleeves that can service multiple rows of associatedopenings that are axially displaced.

FIGS. 4-6 correspond to FIGS. 1-3 with the only difference being theshroud 29 having an end 32 that is past the openings 40 so that thepassage 34 goes directly to the ports 40. Here, as opposed to FIGS. 1-3,once the flow from the formation 14 passes through the shroud 29 itdoesn't have to pass through that shroud 29 a second time. In all otherrespects the method is the same. In FIG. 4 the valves 24 and 26 areclosed for run in. When the string 16 is in position and the barriers 18and 20 are activated, the valve 24 is opened, as shown in FIG. 5, andproppant slurry 28 is delivered through ports 25. There is no crossoverneeded. When the proper amount of proppant is deposited in the interval22, the valve 24 is closed and valve 26 is opened to place the screenmaterial 38 over openings 40 to let production begin. As before, withthe design of FIGS. 1-3 and the variations described for those FIGS.,the same options are available to the alternative design of FIGS. 4-6.One advantage of the design in FIGS. 4-6 is that there is lessresistance to flow in passage 34 because of the avoidance of goingthrough the shroud 29 a second time to get to the ports 40. On the otherhand, one of the advantages of the design of FIGS. 1-3 is that theinside dimension of the string 16 in the region close to valve 26 can belarger because the shroud 29 terminates at end 32 well below the ports40.

In both designs the length of shroud 29 can span many pipe joints andcan exceed hundreds if not thousands of feet depending on the length ofthe interval 22. Those skilled in the art will appreciate that shortjumper sections can be used to cover the connections after assembly sothat the passage 34 winds up being continuous.

FIGS. 7-9 work similarly to FIGS. 1-3 with the only design differencebeing that the shroud 29 is not used because the application for thisdesign is for rather short intervals where a bypass passage such as 34around a shroud 29 is not necessary to get the desired production flowrates. Instead valve 26 has a plurality of screen sections 38 that canbe aligned with axially spaced arrays of openings 40. In this case aswith the other designs, the valves 24 and 26 can be located within oroutside the tubular string 16. In all other ways, the operation of theembodiment of FIGS. 7-9 is the same as FIGS. 1-3. In FIG. 7 for run inthe valves 24 and 26 are closed. The string 16 is placed in position andbarriers 18 and 20 define the producing zone 22. In FIG. 8, the valve 24is opened and the gravel slurry 28 is squeezed into the formation 14leaving the gravel in the interval 22 outside of openings 40. In FIG. 9the gravel packing and frac is completed and the valve 24 is closed.Then valve 26 is opened placing screen material 38 in front of openings40 and production can begin. In essence, valve 26 with its screensections 38 and openings 40 act as a screen that is blocked for run inand gravel deposition and frac and then functions as a screen forproduction. Again multiple assemblies of valves 24 and 26 can be used sothat if one fails to operate another can be used as a backup. In thesame manner if one set of screen sections 38 clog up, another sectioncan be placed in service to continue production.

FIG. 10 illustrates a valve 50 that uses as sliding sleeve 52 toselectively cover ports 54. The ports 54 are closed in FIG. 10 and openin FIG. 11. A latch profile 56 is provided adjacent each sleeve 52. Anarray of valves 50 and associated ports 54 is envisioned. Theconfiguration of the latch profile 56 is preferably unique so as toaccept a specific screen assembly 58, one of which is shown in FIG. 13.Each screen assembly has a latch 60 that is uniquely matched to aprofile 56. FIG. 12 shows a screen assembly 58 that has a latch 60engaged in its mating profile 56. In that position a screen 62 has endseals 64 and 66 that straddle ports 54 with sleeve 52 disposed touncover the ports 54. One or more such assemblies are envisioned in aninterval 22 between isolators 18 and 20 in the manner described before.In operation, the ports 54 are closed for run in as shown in FIG. 10.After getting the string 16 into position and setting the barriers (notshown in FIG. 10) to define an interval 22, as before, the ports 54 areexposed and gravel slurry is forced into the formation as the formationis fractured. At this time the screen assembly 58 is not in string 16.When that step is done and the excess slurry is circulated out, thevalves 50 to be used in production are opened. A screen assembly 58 witha latch 60 that matches the valve or valves 50 just opened is deliveredinto the string 16 and secured to its associated profile 56. In thismanner, the ports 54 that are now open each receive a screen assembly 58and production can begin. Any order of producing multiple intervals canbe established. The screen sections 58 can be dropped in or lowered inon wireline or other means. They are designed to release with an upwardpull so if they clog during production they can be released from latch56 and removed and replaced to allow production to resume. The screenassemblies can have a fishing neck 68 to be used with known fishingtools to retrieve the screen section 58 to the surface. One screensection can cover one array of ports 54 or multiple arrays, depending onits length and the spacing between seals 64 and 66.

Optionally, the shroud 29 of from the other embodiments can be combinedinto the FIGS. 10-13 embodiment and it can be positioned to come justshort of ports 54 or to straddle them as previously described and forthe same reasons.

The above description is illustrative of the preferred embodiment andmany modifications may be made by those skilled in the art withoutdeparting from the invention whose scope is to be determined from theliteral and equivalent scope of the claims below.

1. A completion assembly, comprising: a tubular housing defining a wall;at least one first valved port in said wall selectively movable betweena closed and a open position wherein said port is substantiallyunobstructed; at least one second valved port selectively movablebetween a fully closed and a second position where flow through saidsecond valved port is screened.
 2. The assembly of claim 1, wherein:said wall comprises an outer surface and at least one porous shroudmounted to it that defines an annular passage about said outer surfaceof said wall.
 3. The assembly of claim 2, wherein: said shroud spansover at least one said second valved port.
 4. The assembly of claim 2,wherein: said passage is sealed at opposed ends to said outer surface.5. The assembly of claim 1, wherein: said valved ports comprise slidingsleeve valves.
 6. The assembly of claim 5, wherein: said second slidingsleeve valve comprises a plurality of ports on its sliding sleeve thateach can be aligned in tandem to openings in said wall such that flowthrough the aligned ports is screened.
 7. A completion assembly,comprising: a tubular housing adapted to be included in a tubular stringfor placement downhole, said housing comprising at least one valved portand at least one component of a pair of components adjacent said valvedport; a screen assembly comprising the other of a pair of componentsneeded to interact to support said screen in said tubular in a positionstraddling said valved port, said screen insertable into said housingthrough said string after said string is positioned in a wellbore. 8.The assembly of claim 7, wherein: said housing comprises a profile andsaid screen comprises a latch to engage said profile.
 9. The assembly ofclaim 8, wherein: said latch and profile are uniquely matched to engageeach other whether said screen is lowered or released to drop throughthe string and into said tubular housing.
 10. The assembly of claim 7,wherein: said housing comprises a plurality of valved ports with eachport having one component of a pair of components adjacent said valvedport and with each said component being distinct from the others; saidscreen assembly comprises a plurality of screens each having the otherof a pair of components needed to interact to support said screen insaid tubular in a position straddling said valved port, said othercomponents associated with said screens each uniquely configured toengage a specific mating component on said housing.
 11. The assembly ofclaim 10, wherein: said valved ports are selectively opened and closedwith a sliding sleeve; said screens each straddle at least one valvedport and its associated sliding sleeve and further comprise seals nearopposed ends of each said screen.
 12. The assembly of claim 7, wherein:said valved port is selectively opened and closed with a sliding sleeve;said screen straddles said valved port and said sliding sleeve andfurther comprises seals near opposed ends of said screen.
 13. Acompletion method, comprising: delivering a housing having at least onefirst and at least one second valved ports to a desired locationdownhole; performing a downhole operation through said first valved portwhen it is open; closing said first valved port after said performing ofdownhole operation; opening said second valved port, after closing saidfirst valved port, in a manner to allow production flow into saidhousing to pass a screen associated with said second valved port. 14.The method of claim 13, comprising: performing a gravel pack andformation fracture as said downhole operation.
 15. The method of claim14, comprising: providing at least one porous shroud around said housingto define a flow passage around said housing; depositing said graveloutside said shroud; and taking production flow through said passageinside screen and toward said screen associated with said second valvedopening.
 16. The method of claim 15, comprising: sealing said passage tosaid housing on opposed ends of said shroud; and positioning said shroudoffset from said second valved port.
 17. The method of claim 15,comprising: sealing said passage to said housing on opposed ends of saidshroud; and positioning said shroud over at least one said second valvedport.
 18. The method of claim 13, comprising: providing a first slidingsleeve for said first valved port and a second sliding sleeve for saidsecond valved port; providing at least one port in said second slidingsleeve with a screen covering it for selective alignment with at leastone associated port in the housing.
 19. The method of claim 14,comprising: sealing said housing in the wellbore to isolate at least oneproducing zone having at least one set of first and second valved portstherein.
 20. The method of claim 19, comprising: providing at least oneporous shroud around said housing to define a flow passage around saidhousing; depositing said gravel outside said shroud; and takingproduction flow through said passage inside screen and toward saidscreen associated with said second valved opening.
 21. A completionmethod, comprising: delivering a housing having at least one valved portto a desired location downhole; performing a downhole operation throughsaid valved port when it is open; inserting a screen into said housingafter performing said downhole operation; supporting said screen whileit covers said valved port; and taking fluids into said housing throughsaid screen.
 22. The method of claim 21, comprising: performing a gravelpack and formation fracture as said downhole operation.
 23. The methodof claim 22, comprising: providing interacting components on saidhousing and said screen that engage for placement of said screen oversaid valved port.
 24. The method of claim 21, comprising: performingsaid inserting by lowering or dropping said screen into said housing.25. The method of claim 23, comprising: providing a plurality of valvedports with each having a unique interacting component on said housingdesigned to accept a matched component on said screen for specificplacement of each screen in said housing.
 26. The method of claim 25,comprising: providing unique profiles in said housing and a matchinglatch on each screen to specifically locate and support each said screenin said housing.
 27. The method of claim 26, comprising: isolating aplurality of producing zones around said housing where each zone has avalved port capable of accepting an inserted screen after performingsaid gravel pack and fracturing.
 28. The method of claim 22, comprising:providing at least one perforated shroud around said housing; depositinggravel outside said shroud; taking production flow through a passage insaid shroud to bypass some of the gravel pack before reaching saidscreen.
 29. The assembly of claim 5, wherein: said screen is mounted onsaid sliding sleeve.
 30. The assembly of claim 5, wherein: said screenis mounted on said housing.